Fish breathing rapidly, only at night

[cj7jeep81]

Little background first. I have a 125 gallon tank, with about 100 pounds of rock, and a 3-4" sand bed. I have a 75 gallon sump in my basement, with a reef octopus 200 skimmer, and a 13 gallon refugium with chaeto (lights are on a reverse cycle from main tank, but there is overlap). For flow, I have a Reeflo Dart on a closed loop.

Tank has been up about 4 months now. I added a pair of ocellaris clowns and a lawnmower blenny about 3 months ago. Added a female lyretail anthias and a blue hippo tang about 1.5 months ago.
For corals, I have some polyps, a couple different acans, a favia, a poscilipora, a frog spawn, and a lobophylia.

Everything had been going good. All the fish eat really well, and have all grown noticeably. About a month ago, I noticed some white stuff on the tang on his gills. After research, I determined it was a lymphocyst, and after a couple weeks, it all fell off. Throughout all of this, he ate like a pig. Last night (towards the end of the lighting cycle), I noticed the blue tang breathing incredibly fast, and laying more on his side (not completely unusual, as he always sleeps on his side in the rocks). I also noticed the frog spawn was retracted, and the poscilipora's polyps were all pulled in. All the rest of the corals looked fine.

I checked levels, and everything seemed fine, so I didn't know what I could do but wait. This morning, everything was back to normal, and the hippo tang was acting perfectly fine and eating like a pig again. Now tonight, same thing. Hippo breathing very rapidly, frog spawn retracted, poscilipora retracted, but now my lobo is also all shrunken.

Any ideas what could be wrong? I haven't changed anything lately, but something definitely isn't happy.

 

[Anemone]

What's your surface agitation like? During lights out, the corals and surface algal films stop photosynthesizing, meaning rather than being net oxygen producers, they become oxygen consumers, meaning the oxygen levels in the water can drop, causing issues for fish. If it gets critical, a single fish dying (due to lack of oxygen - basically suffocation) causes a bacterial explosion, consuming more oxygen, causing more fish to die, causing more bacterial growth, consuming more oxygen, etc, etc, etc. I've seen entire tanks wiped out overnight.

The good news is that simply redirecting whatever water movement there is in the tank to make sure it causes surface agitation will generally solve the problem.

I'm not sure if this is your situation, but the fast breathing of your larger fish, only at night, seems like a plausible scenario...

Kevin

 

[drej424]

Try doing a water change and using an air pump. If it is being caused by low oxygen, that should help. If there's no improvement, it's probably being caused by something else.

 

[cj7jeep81]

there is a ton of surface agitation, so I don't think that's the issue. Also, this happens in the evening, but while the lights are still on. My lights turn off at 8:30pm, and I've been noticing this starting around 8pm. The blue tang is the largest fish in the tank, but not by much. He's pretty small (maybe 2 or 2.5" long).

I can find an air pump, but with a lot of surface agitation, and a skimmer running all the time, how big of a pump would I need? I can probably do a water change on Sunday, but right now don't have any water mixed up to make any appreciable change. Since setting up the tank, I've been doing monthly water changes, and changing out about 35 gallons at a time.

Also if it helps, all of my corals are small. Biggest is probably the lobo, and it's roughly 2"x3". Rest are frags.

 

[Anemone]

What's your pH reading? Generally, pH is at it's highest at lights out, so perhaps your pH is spiking too high?

Kevin

 

[cj7jeep81]

I checked that last night, and it was 7.8. However, that's assuming the kits are good, which I'm not 100% sure. I bought them used from a guy selling other stuff, so I have no idea how old they are, or if a PH test kit can go bad.

Looking at the tang now, he looks to be acting normal. Will be able to tell more in a few hours when the lights come on.

 

[Trigeek]

Do you have any macro algae in or attached to the system? If there is a lot, and lights are out on this at night, there may be a drop in O2 at that time due to lack of photosynthesis.

 

[cj7jeep81]

Do you have any macro algae in or attached to the system? If there is a lot, and lights are out on this at night, there may be a drop in O2 at that time due to lack of photosynthesis.

I do have some macro algae in my sump. Mostly chaeto, and some other. My lights on the tank are on from 9:30am to 8:30pm. My lights on my refugium are on 18 hours a day. They come on at 4 or 5pm (can't remember which), and are then on for 18 hrs. The one bunch of chaeto is decent sized. Bought a ziplock bag full at a frag swap, and I think it's grown, but hard to say as it expanded a lot when I put it in the tank. My refugium is roughly 13 gallons (10"x18"x18" I think), and the big mass of chaeto doesn't even fill up 20% of that.

I could definitely remove some though, if the thought is that might help.

 

[cj7jeep81]

I've got an air pump and a couple of air stones. Ok to set this up in my sump? I'd rather not have all the bubbles from the stones in my display tank, and it would be a lot easier to set up in the sump.

I would assume it would still oxygenate just fine, right?

 

[cj7jeep81]

Last night, everything seemed fine except the lobo coral. I feed him some mysis (I hadn't been feeding him as often), and he perked up and looks great today. However, tonight the poscillipora is closed up, and the hippo tang is breathing rapidly again. Added the air pump to the return section of my sump, so we'll see if he looks any better in the next 20 minutes before the lights go out (I assume it wouldn't take too long to help oxygenate the water).

 

[cj7jeep81]

Last night the hippo tang was breathing fast again, so I added an air pump to the sump. I don't know the specs of it really, other than its one my mom used on her 55 gallon fresh water tank in the past. I have it powering a 10" air stone and a 5" air stone (both new) in the return section of my sump.

Tonight around 6:30 everything looked fine. Lobo was all inflated, hippo was normal and eating. Around 7:30, I check again and the lobo is complete deflated (can see the spikes of the skeleton making the flesh spikey), and the hippo is breathing fast again.

Does anyone have any idea what to look for?

 

[cj7jeep81]

Anyone else with any ideas? Still going through the same pattern of around 7:45 or 8pm at night the hippo tang and some corals looking bad, then tomorrow everything will be fine.